A potential field method for bottom navigation of autonomous underwater vehicles

The potential filed method is proposed to solve the bottom navigation problem of an underactuated autonomous underwater vehicle, including the bottom avoidance problem and the bottom following problem. The desired depth is treated as a stationary goal and the sea bottom is a moving obstacle in the bottom avoidance problem. And the desired altitude above the bottom is a moving goal and the maximum designed depth acts as a stationary obstacle in the bottom following problem. To improve the performance, the slope of sea bottom is added to the conventional potential forces as the relative velocity between the vehicle and the bottom, resulting in the dynamic potential field which is originally addressed for motion planning of mobile robots. A two layered hierarchical architecture is used to solve the motion control problem. The preliminary simulation results are provided to demonstrate that the proposed potential field based controller is easy for implementation with a satisfying performance.